Various methods are used by e-commerce sites and systems to help customers locate products of interest. Some systems use market-based data to promote products. For example, an e-commerce site may identify or recommend to potential customers products that are best-selling or most popular among other customers, as determined from collected behavioral data. Some e-commerce systems recommend products based on what other customers with similar purchase or viewing histories have purchased.
Although these methods are sometimes useful, they ordinarily do not take into consideration the purpose for which customers purchased particular products.